System for reinforcing towers and the like

ABSTRACT

A system for reinforcing a tower is disclosed. The system includes a number of vertically elongated primary support risers. Each riser is attached to the tower at a series of spaced apart locations.

BACKGROUND OF THE INVENTION

This invention relates to reinforcing systems and constituent parts for reinforcing vertically elongated towers and like structures against more or less horizontally applied wind loads and the like. While these towers may be freestanding, self-supported, guyed or monopole towers, the invention will be described and illustrated here in connection with a monopole tower for purposes of clarity. It will be understood that it is not intended to limit this invention to its use with monopole towers.

The erection of monopole and other towers has become an important industry as those towers are used to support antennas for wireless communications cell sites; for light fixtures used at stadiums, along highways and in parking lots; and for other purposes. Other tall towers are essential for radio, television and other broadcasting systems. The number of monopole and other towers has more than quadrupled since the inauguration of cellular telephone systems. Cellular telephone carriers are sharing the use of towers as a cost-effective method of delivering cellular telephone system service, and of sharing the expense of maintaining the towers.

Cellular telephone towers are typically between 65 and 250 feet high, and each tower may support a number of antennas, some of which are large. These large antenna and support systems can experience high wind loads, and these wind loads must be transferred to the tower structure. Currently, at least some of the old towers will not pass structural analysis tests required by state, county and local municipalities. These and other towers require reinforcement to pass mandated structural load analysis tests. Reinforcement can be difficult and costly, due to the logistics involved in adding components to the tower structure; installation time and labor costs; and actual or potential interference of the reinforcements with the tower antennas or other operating equipment.

This invention provide a system for reinforcing monopole and other towers and vertically elongated structures which minimizes the cost of bringing reinforcement parts, labor and support features to the tower site; which minimizes the cost of reinforcement installation time and labor costs; and which minimizes the interference of the reinforcing structure with the tower antennas or other tower access or operating equipment.

While the invention will be described in connection with several preferred embodiments, it will be understood that it is not intended to limit the invention to these embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. In particular, it is not intended to limit the invention to its use with a monopole tower. As noted above, the invention may be used in connection with guyed towers, self-supported towers, free standing towers, or other vertically elongated structures in need of reinforcement. The invention may also be used to form, by itself, a strong and efficacious tower.

Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. Throughout the drawings, like reference numerals referred to like parts.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of an exemplary monopole tower equipped with reinforcements embodying the novel reinforcing system.

FIG. 2 is a fragmentary isometric view illustrating the reinforced base of an exemplary monopole tower and the adjacent foundation.

FIG. 3 is a fragmentary elevational view of the exemplary monopole tower illustrating the attachment of reinforcing elements to the tower structure.

FIG. 4 is a fragmentary isometric view of reinforcement elements attached to a portion of an exemplary monopole tower.

FIG. 5 is an isometric view of a typical reinforcing element.

FIG. 6 is an isometric view of a lateral support bracket.

FIG. 7 is a top plan view of the lateral support bracket shown in FIG. 6.

FIG. 8 is an isometric view of a device for attaching reinforcement pipe sections to one another.

FIG. 9 is an isometric view of an exemplary monopole tower similar to FIG. 1 but illustrating a reinforcement connecting collar.

FIG. 10 is a fragmentary isometric view illustrating in further detail the reinforcement connecting collar suggested in FIG. 9.

FIG. 11 is a fragmentary isometric view illustrating a chair element used to reinforce the interconnection between the tower base plate and the tower monopole.

FIG. 12 is an exploded view showing in further detail parts of the reinforcement connecting collar.

FIG. 13 is an isometric view of an exemplary monopole tower similar to FIGS. 1 and 9 but illustrating an alternate embodiment of the reinforcing connecting collar.

FIG. 14 is a fragmentary isometric view similar to FIG. 10 but illustrating in further detail the alternate embodiment of the reinforcement connecting collar suggested in FIG. 13.

FIG. 15 is an exploded view similar to FIG. 12 showing in further detail parts of the alternate embodiment reinforcement connecting collar.

FIG. 16 is an isometric view, similar to FIGS. 1,9 and 13 showing an exemplary monopole tower fitted with yet another embodiment of the connecting collar.

FIG. 17 is a fragmentary isometric view similar to FIGS. 10 and 14 showing in further detail the embodiment of the connecting collar suggested in FIG. 16.

FIG. 18 is an exploded view similar to FIGS. 12 and 15 showing in further detail parts of the alternate embodiment reinforcing connecting collar shown in FIGS. 16 and 17.

FIG. 19 is a fragmentary isometric view showing an alternate embodiment of the tower base plate and foundation upon which it is mounted.

FIG. 20 is a fragmentary isometric view similar to FIGS. 10, 14 and 17 showing in further detail yet another embodiment of a connecting collar and the associated reinforcing elements.

FIG. 21 is an exploded view showing in further detail the reinforcing collar of FIG. 20.

FIG. 22 is an isometric view showing a reinforcing element as it appears when attached to a portion of the exemplary monopole tower.

FIG. 23 is a top plan view showing a mounting bracket as it appears when secured to the exemplary monopole tower.

FIG. 24 is a top plan view of yet another embodiment of a connecting collar and the associated reinforcing elements.

FIG. 25 is a fragmentary elevational view of the connecting collar and associated reinforcing elements shown in FIG. 24.

FIG. 26 is a fragmentary elevational view of primary support elements and element interconnectors.

FIG. 27 is a fragmentary elevational view similar to FIG. 26 of primary support elements and associated tension strap coupling elements.

FIG. 28 is a fragmentary elevational view of an exemplary monopole tower foundation, base plate, secondary base plate and associated vertical reinforcing elements.

FIG. 29 is a top plan view of the base plate, foundation, secondary base plate and associated vertical reinforcing elements shown in FIG. 28.

DETAILED DESCRIPTION

While the invention will be described in connection with several preferred embodiments, it will be understood that it is not intended to limit the invention to these embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. In particular, it is not intended to limit the invention to its use with a monopole tower. As noted above, the invention may be used in connection with guyed towers, self-supported towers, free-standing towers, or other vertically elongated structures in need of reinforcement. The invention may be also used to form, by itself, a strong and efficacious tower.

Turning first to FIG. 1, there is shown an exemplary free-standing tower, here illustrated as a monopole tower 50. This tower 50 includes a central vertically elongated monopole structure 52 which may be subjected to wind loads W or similar horizontally applied forces. A structure top 54 is adapted to mount antennas 56 or other equipment, which subject the structure to a vertically applied load L. A primary base plate structure 58 affixes the tower to a foundation 59.

A reinforcing system structure 60 comprises a plurality of vertically elongated primary support risers 64 which are here located outside the central vertically elongated monopole structure 52. In accordance with invention, each of these risers 64 is attached to the central vertically elongated monopole structure 52 at spaced apart points as suggested in FIG. 3 and elsewhere. As explained in further detail below, these attachment devices can include straps 66 or any equivalent securement mechanisms. Tension straps 67 can be used to surround all the risers 64 so as to maintain the alignment of the risers 64 as shown in FIG. 27.

As suggested in FIGS. 1, 2, 9, 10, 13, 14 16, 17 and elsewhere, the support risers 64 are here located outside the central vertically elongated monopole structure 52. In accordance with another aspect of the invention, however, the risers 64 can be affixed inside the central pole structure 52 if desired and if the central structure 52 can accommodate the risers 64. As illustrated here, these risers 64 comprise hollow pipes. As such, the pipes have a substantially circular cross-section. They can, however, have cross sections taking the form of a triangle, rectangle, oval, or any other shape which provides maximum surface, so as to provide maximum modulus and consequent maximum stiffening effect to the support riser and the supported tower. The hollow support risers 64 can contain internal reinforcement webbing, in accordance with yet another aspect of the invention.

As shown in FIGS. 2, 19 and elsewhere, the central tower structure 52 is affixed to the foundation 59 by the base 58. As shown and particularly in FIG. 2, a series of bolts 70 of suitable strength mounted on and in the foundation 59 accept the overlying base plate 58 which is welded or otherwise secured to the monopole 52. To strengthen the poll/base connection in accordance with the invention, fins 72 are welded to the reinforcing risers 64 and also to the base plate 58. If the fin connection of a particular riser 64 to the base plate 58 would be inhibited by a bolt 70, a chair-like structure 74 formed of horizontally and vertically arrayed fins can be provided as particularly suggested in FIGS. 2 and 11. If required by good engineering design, a second base plate 57 can be affixed to the pole 52 at a position above the primary base plate 58, and the plates can be interconnected by fins 74, bolts, or other known devices as suggested in FIG. 28.

As shown in FIGS. 1, 9, 13, 16 and elsewhere, these risers 64 can extend up the sides of the exemplary tower 64 a considerable distance. In the interests of economy, and as explained above, the risers can be formed of strong pipe sections which are joined by primary support coupling elements 80 as shown in FIG. 26. Alternatively, as shown in FIG. 8, pipe splice devices 61 can include a threaded rod nipple 63 which mates with the pipe sections 64 or, alternatively, plugs 64 a which are, in turn, fitted into the adjacent pipe sections.

Lateral support brackets 82 as shown in FIGS. 4 and 5 secure the risers 64 to the central tower outlet 52 at the upper end of the risers. Here, these securing devices 82 each include a flange 84 which is bolted to the tower 52; and a threaded element 86 is welded or otherwise affixed by means not shown to the pipe portion of the risers 64. A nut 88 can be turned down the threaded element 86 so as to place each of the riser devices 64 in a desired amount of compressive force.

At intermediate points, the risers can be secured to the tower structure 52 by lateral support brackets 85 shown in FIGS. 6 and 7. These brackets can take any convenient yet effective form. Here, they include one or two wings 87 and fastening devices such as bolts of the necessary strength.

Alternatively, the risers 64 can be secured at their upper ends to the pole 52 by grillage transfer cages 90. As shown in FIGS. 10, 12, 15, 17, 18, 14, 21 and 25, these grillage interconnectors or collars 90 take the form of one, two or more rings 92 which are welded or otherwise secured to connector fins 94. In this embodiment of the invention, these fins 94 are bolted or otherwise secured together by threaded elements 96. The rings 92 are secured to the upper ends of the risers 64. Additional stiffening and securement action can be provided by plates 98 welded between the rings 92 as suggested in FIG. 10 to provide a closed case. Spacer fins or shims can be provided to adjust the fit of the rings 92 with the surrounded tower structure. Adjustment can also be provided by threaded nipples 99 as shown in FIG. 24. 

1. A system for reinforcing a tower, comprising, in combination, a vertically elongated structure which may be subjected to wind loads or similar horizontally applied forces, a structure top adapted to mount equipment which subjects the tower to a vertically applied load, and a base for affixing the tower to a foundation; the reinforcing system comprising a plurality of vertically elongated primary support risers, each riser being attached to the tower at spaced apart locations.
 2. A system according to claim 1 wherein said vertically elongated primary support risers are each attached to the base.
 3. A system according to claim 1 wherein said tower is a monopole.
 4. A system according to claim 1 wherein said tower is a free-standing structure.
 5. A system according to claim 1 wherein said tower is a self-supported structure.
 6. A system according to claim 1 wherein said tower is a guyed structure.
 7. A system for reinforcing a tower or like structure which includes a central vertically elongated structure which may be subjected to wind loads or similar horizontally applied forces, a structure top adapted to mount equipment which subjects the structure to a vertically applied load, and a primary base plate structure for affixing the central structure to a foundation, the reinforcing system comprising a plurality of vertically elongated primary support risers located outside the central vertically elongated structure, each riser being attached to the central vertically elongated structures at spaced apart locations.
 8. A system according to claim 7 wherein said vertically elongated structure is a monopole.
 9. A system according to claim 7 wherein said risers comprise hollow pipe lengths.
 10. A system according to claim 9 wherein said risers comprise pipes having polygonal cross-sectional shapes.
 11. A system according to claim 7 further including a secondary base plate affixed to the vertically elongated structure and to the primary base plate at a location above and spaced apart from said primary base plate.
 12. A system according to claim 7 further including at least one fin plate attached to the base plate and to a primary support riser.
 13. A system according to claim 7 further including a chair element comprising at least two vertical fin plates located adjacent to a bolted base-plate/vertically elongated structure interconnection.
 14. A system according to claim 13 further including a horizontal fin plate affixed to said vertical fin plates and to said vertically elongated structure.
 15. A system according to claim 14 further including an additional vertical fin plate affixed to said horizontal fin plate and to said vertically elongated structure at a position above said two vertical fin plates.
 16. A system according to claim 1 wherein said vertically elongated support risers comprise riser section elements connected to each other in end-to-end array.
 17. A system according to claim 16 further including connection devices for interconnecting adjacent sections of the vertically elongated support risers.
 18. A system according to claim 7 further including lateral support bracket devices for connecting the vertically elongated support risers to the vertically elongated tower structure.
 19. A system for reinforcing a monopole tower or like structure which includes a central vertically elongated structure which may be subjected to wind loads or similar horizontally applied forces, a structure top adapted to mount equipment which subjects the structure to a vertically applied load, and a primary base plate structure for affixing the central structure to a foundation, the reinforcing system comprising a plurality of vertically elongated primary support risers located inside the central vertically elongated structure, each riser being attached to the central vertically elongated structure at spaced apart locations.
 20. A system according to claim 1 wherein said vertically elongated primary support risers are hollow but contain reinforcement webbing therein.
 21. A system according to claim 1 wherein at leased one of said vertically elongated primary support risers has cross-sectional modulus of maximum surface so as to provide maximum stiffening effect to the support riser and the supported tower.
 22. A system according to claim 1 further including a grillage device for connecting the support risers to the central vertically elongated structure.
 23. A system according to claim 22 wherein said grillage device includes at least one ring element for engaging at least one riser.
 24. A system according to claim 22 wherein said grillage device includes at least one fin element and at least one ring element secured to said fin element for strengthening the riser-central vertically elongated structure interconnection. 